(M)ulti (U)sers (D)ungeon

What is a MUD?

A MUD is a text-based adventure game that involves moving in directions, killing mobiles, and getting objects, along with communicating and competing with others doing the same thing.

What is a DikuMUD?

The DikuMUD that is most common usually has a town called Midgaard and some "stock" areas, along with some areas that are original. All run off of a similar basic coding structure, but most have modified their MUD to look original.